Film unwinding mechanism



FILM UNWINDING MECHANISM Filed June 50, 1939 Ey {Mu dll/Z 0%/ HraR/wsr Patented Feb. 16, 1943 FILM UNWINDING MECHANISM Jan Jesayas Hardenberg, Eindhoven, Netherlands, assignor, by mesne assignments, to Hartford National Bank and Trust Company, Hartford, Conn., as trustee Application June 30, 1939, Serial No. 282,293 In Germany July 25, 1938 3 Claims.

My invention relates to a mechanism for winding and particularly for unwinding hand-shaped carriers, such as sound and/or picture illms.

The main object of my invention is to provide a simple mechanism for unwinding bandshaped carriers.

A further object is to provide a winding and unwinding device in which the use of flexible driving shafts is eliminated.

A still further object is to provide a winding and unwinding mechanism the reel of which can also be used as a storage reel or a feed reel.

Further objects and advantages of my invention will appear as thedescription progresses.

In accordance with the invention and for the winding of the lm I use a rotary member having an external driving surface and support this member from a driving shaft, I loosely suspend a cylindrical take-up body from this driving member, either directly or through the lilm which is wound into a roll against the internal surface of the body.

The take-up body with the film wound against its internal surface into an annular roll may be used as a supply reel in an electro-optical reproducing system or a projecting system, in which case, separate re-winding of the lm is unnecessary. For this purpose I provide means to prevent undesired unwinding of the iilm at the center of the roll and also provide in the outer wall of the take-up body an aperture through which the film is withdrawn.

In order that the invention may be clearly understood and readily carried into effect I shall describe the same in more detail with reference to the accompanying drawing in which:

Figure 1 is a side view of a winding mechanism suitable for use in conjunction with the un- Winding mechanism of the invention,

Fig. 2 is a sectional view along line 2-2 of Figure 1,

Fig, 3 is a side view of another form of the winding device of Fig. 1,

Fig. 4 is a section along line 4 4 of Figure 3,

Fig. 5 is a partly sectionized side view of an unwinding device according to an embodiment of the invention,

Fig. 6 is a sectional view along line 6-6 of Figure 5.

The winding device illustrated in Figures 1 and 2 comprises a driving roller I I provided with two ilanges I9 and an external driving surface I3. Roller II is lixedly secured to the end of a shaft 34 which is rotatably mounted on a suitable ilxed bearing I8 and is rotated in the direction of the arrow B by suitable driving means (not shown) so that the driving surface I3 has the speed of the film.

An annular winding reel or take-up body I2 surrounds roller II and has an internal surface I4 whose width is slightly less than that of the surface I3 between anges I9. Thus, body I2 is adapted to be loosely suspended from surface I3 and to be driven thereby.

A lm I0, which may be a sound film, a picture film, or a sound-picture lm, has its end secured to body I2. For this purpose an end portion of the lm extends through a slot I6 in body I2 and passes beneath 'a clip Il secured to the body, l

At the beginning of the winding the end of lm I0 is secured to body I2 and at this time the surface I4 is in direct contact with surface I3. Upon rotation of roller II in the direction of the arrow, the body I2 is rotated thereby with the result that the lllm I0 is drawn in beween surfaces I3 and I4. Upon continued rotation of roller II, the body I2 is rotated in the same direction so that the :film is wound into an annula-r roll or coilv I5.

Thus, the turns of coil I5 are supplied to the take-up body -I2 internally thereof and engage the internal surface of the preceding turns without the occurrence of any mutual displacement. When the coil I5 is to be unwound, the beginning of the lm is on the outside of the coil so that the latter can be unwound immediately and without any re-winding.

In the above-described device the required frictional pressure between iilm I0 and the driving surface I3 is obtained by the weight of the take-up body l2 which, with or without the iilm already wound up, is loosely suspended from roller II so that the film is pressed against the driving surface I3 by gravity. The two flanges I9 ensure correct guiding of the film.

The device shown in Figs. 3 and 4 is similar to that of Figs. 1 and 2 and similar parts are designated by the same reference numerals. However, in Figs. 3 and 4 the body I2 is replaced by a body 5I having an internal take-up surface 52 and two flanges 20 so that the film coil I5 is Wound up in a confined space. This construction is particularly useful for films having a small width, for instance, 5 mms. and even less, which lms without any supporting means could not be wound into a self-supporting roll which could be readily handled. The driving roller II is replaced by a flange-less roller 53 which eX- tends into the space between flanges 20. To

increase the friction between lm Il) and roller 53, the latter is provided with surface layer 2| of friction material, such as rubber.

Figs. and 6 illustrate a take-up device which is similar to that of Figs. 3 and 4 but can be used both as a storage reel and as a feed reel. In Figs. 5 and 6, hollow body 5I with the film roll I5 therein is closed on the inside by an insert core A to prevent undesired unwinding of the film at the center of the roll.

If this storage reel is to be used as a supply reel in an electro-optical reproducing system or in a projector the lm coil I5 should be centered at its inside on a core so that it can be unwound from without. Furthermore, the coil I5 should be capable of rotating loosely in the hollow body I2 so that the film I0 can pass freely through the slot I6. In addition it is preferable that the core may be used with film rolls of different length lms and consequently of different inside diameters.

As shown in Figures 5 and 6 the core A comprises a mandrel having a cylindrical portion 23 and a shaft portion 33. A plurality of curved lever arms 24 are rotatably mounted on pins 26 xed to a ring 21 and have their end surfaces 25 engaging the inside of the film coil I5. Each of the levers 26 has a forked inner end 28 which engages a pin 29 mounted on a central disc 30 which is secured to the end of the mandrel portion 23 by screws 32. If ring 2l is rotated relatively to disc 30, the pins 26 will be displaced tangent-ially relatively to the pins 29 with the result that the ends 25 of levers 24 will be moved either inwardly or outwardly. The ring 21, when in the desired position, can be forced tightly against the mandrel 23 by means of a set-screw 3I so that the lever arms will be retained in that position which centers the coil I 5.

When unwinding the film, the body 5I is placed in a horizontal plane afterthe coil I5 is mounted on the core, the core 23 being supported in a suitable support by means of shaft 33. The iilm end IU, which has already-been passed out through slot I6 at the beginning of the winding operation, is placed in engagement with the eonveyer members of the film apparatus (not shown) and is unwound by them from the coil I5 which is supported on the mandrel A and is free to move within the body I2 which remains lstationary. The unwinding operation is effected in the usual manner from the outside inwards, each turn of the coil conserving the same diameter at which it was wound originally so that there is no sliding between adjacent turns and the lm is not damaged by scratches.

The take-up device and feed spool according to the invention are particularly advantageous for use of replacing the usual gramophone records in systems for reproducing speech and music. The size of the storage reel may be about equal to two gramophone records in the case of a lm having a width of about 31/'2 mm. and its duration of play is from 10 to 15 minutes, according to the thickness of the film, so that it surpasses the usual gramophone records not only in quality but also in recording duration.

Although I have described my invention in connection with specific examples and details of construction, I do not wish to be limited thereto because obvious modifications will readily present themselves to one skilled in the art.

What I claim is:

1. A lm unwinding device comprising an annular body having an internal take-up surface and adapted to receive an annular roll of lm, the periphery of said body being provided with a slot through which the lm passes during the unwinding,acore within the annular body adapted to support the film during unwinding, said core comprising a central member, an annular adjusting member surrounding the central member and a plurality of levers pivoted on said adjusting member, the outer portions of said levers forming an annular supporting surface for the film roll and the inner portions thereof being secured to said central member, and means to secure said adjustment member vto said central member.'

2. A film unwinding device comprising an annular body having an internal take-up surface and inwardly extending flanges forming a confined space adapted to receive an annular roll of lm, the periphery of said body being provided with a slot through which the lm passes during the unwinding, a core within the annular body adapted to support the lm during unwinding, said core comprising a central member, an annular adjusting member surrounding the central member and a plurality of levers pivoted on said adjusting member, the outer portions of said levers forming an annular supporting surface for the lm roll and the inner portions thereof being secured to said central member, and means to secure said adjustment member to said central member.

3. A film unwinding device comprising an annular body having an internal take-up surface and adapted to receive an annular roll of film, the periphery of said body being provided with a slot through which the film passes during the unwinding, a core within the annular body adapted to support the film during unwinding, said core comprising a central cylindrical `member having a plurality of pin members extending from an end surface thereof and symmetrically arranged about the axis thereof. an annular adjusting member surrounding the central member and a plurality of curved lever arms pivoted on said adjusting member, the outer portions of said levers forming an annular supporting surface for the lm roll and the inner portions thereof being fork shaped and engaging said pin members, and means to secure said adjustment member to said central member.

JAN JESAYAS HARDENBERG. 

